A quirk is a unique, odd, and sometimes charming trait that makes a person stand out from the crowd. Country comedian Minnie Pearl was known for her quirk of wearing a $1.98 price tag dangling from her hat.
A quirk can be an adorable little habit, like wearing flowery dresses and big sun bonnets or bow ties every day. Someone who has one or many quirks is said to be quirky — a little odd, but usually in a fun way. When it's not being used to describe people's unusual traits, quirk can mean a quick curve, or a groove, that runs along or separates the molding in a building.